Reduction of vasopressor requirement by hydrocortisone administration in a patient with cerebral vasospasm.

A 67-yr-old female received hypertensive, hypervolaemic treatment for cerebral vasospasm after severe subarachnoid haemorrhage. After 3 days of continuous vasopressor infusion and despite adequate hydration and normal cardiac function, the phenylephrine dose had to be increased to obtain the same systolic blood pressure. This tachyphylaxis to phenylephrine infusion was probably caused by down-regulation of alpha adrenoceptors, and was reversed by giving i.v. hydrocortisone.